Normal menstrual cycle: from the first day of bleeding to the first day of the next bleeding, the interval between the two is the length of the menstrual cycle, usually 21-35 days, average 28 days; normal menstrual duration (period): usually 2-8 days, average 4-6 days; normal menstrual volume: 20-60ml, more than 80ml is excessive menstruation. 1) Classification of menstrual disorders: 1) Amenorrhea: primary amenorrhea: age over 13, secondary sexual characteristics have not developed, or age over 15, secondary sexual characteristics have developed, but menstruation is still coming; secondary amenorrhea: menstruation stops for 6 months after normal menstruation is established or stops for more than 3 cycles according to its own menstrual cycle. 2)Menstrual cycle disorder 3)Prolonged menstrual period 4)Excessive or excessive menstrual flow 5)Periovulatory bleeding: bleeding in two periods 2.Consultation time and precautions: 1)Patients with prolonged menstruation should be consulted promptly if their periods exceed 7 days 2)Patients with amenorrhea are generally recommended to be consulted during amenorrhea or when menstruation is overdue 3)Periovulatory bleeding: generally recommended to be consulted during the bleeding phase 4)Menstrual cycle disorder can be consulted at any time 5)Excessive or excessive menstrual flow: a visit on the 2nd-3rd day of menstruation is recommended, and depending on the condition, another visit may be required on the 3rd day of clean menstruation.